Compound steam-engine.



No. 761,125. 'PA'TENTED MAY 31, 1904.

J. B. ALLFREB. COMPOUND STEAM ENGINE.

APPLICATION FILED FEB. 10, 1902.

N0 MODEL.

- A TTOHNE Y UNITED STATES Patented May 31, 1904. v

PATENT OFFICE.

JAMES B. ALLFREE, OF INDIANAPOLIS, INDIANA.

COMPOUND STEAM-ENGINE.

SPECIFICATION formingpart of Letters Patent No. 761,125, dated May 31, 1904. Application filed February 10, 1902. Serial No. 93,328- (No model.)

To all whom, it may concern: v e

Be it known that I, JAMEs B. ALLrREE,-a

citizen of the United States, and aresident of Indianapolis, county of Marion, and State of Indiana, have invented certain new Improvements in Compound Steam-Engines, of which the following is a specification, reference being made to the accompanying drawings, in the different views of which similar letters of reference denote similar parts.

My invention relates principally to compound engines, and I show in the drawings one of a single-acting twin vertical type.

The objects of this invention are to provide an inexpensive means for obtaining high r0- tative speeds, together with the highest attainable economy and with the least number of working parts. I accomplish this by the use of four cylinders, two high-pressure and two'low -.pressure, operating upon the same shaft, the cranks being set directly opposite, whereby the engine is practically balanced. I provide a steam-distributing valve of semicircular form adapted to rock or oscillate in a cylindrical chamber located betweenthe two high-pressure cylinders and just above the two low-pressure cylinders and at right angles to their plane of action, said valve being provided with admission edges on its opposite sides and a port channel or chamber passing through from side to side, running nearly its entire length This port is provided with'both admission and release edges, and below this port-channel or chamber an' exhaust-cavity for the final release of the steam from-the low-pressure cylinders. I actuate this valve by an eccentric controlled by an ordinary automatic sl1aft governor through arocker-arm and connections between valve and eccentric. In action it will be observedthat when the steam is being admitted to one of the highpressure cylinders, which I will designate for illustration as No. 1, the steam is being exhausted or released from the opposite highpressure cylinder, which I will designate as No. 2, and at the same time,through the medium of the chamber or port-channel through the valve, the steam that is being released from high-pressure No. 2 will be admitted to the low-pressure cylinder No. 1, while the exhaust will be released from the low-pressure cylinder No. 2 through the said exhaust-cavity, all during each and every revolution of the engine. By and through the methods and devices herein employed I am enabled to operate the engine without noise at unusually high speeds, requiring practically no attention, and with a minimum wear and destruction of parts, while through compounding I get a higher rate of expansion, and thereby great economy. I attain these objects by the arrangement and construction illustrated in the drawings, in which Figure 1 is a partial vertical sectional view on line 1 1 of the complete engine. Fig. 2 is an end elevation of the engine. Fig. 3 is an enlarged detail sectional view of valve detached.

In the characters of reference, (0 represents the base-casting.

Z2 is the cylinder-casting, here shown as comprising four cylinders in one casting, two larger cylind ers for low-pressure steam and the two smaller cylinders for high-pressure, the latter said cylinders projecting, as seen at 5 5', directly in line with the former low-pressure cylinders, so that a compound piston, or one large atone end and small at the other, is adapted to reciprocate within said cylinders, as shownat c c, said pistons connected in customary manner by connecting-rods d to crankshaft 6, mounted in suitable bearings. 1

f, f, f and f are the steam-ports to the respective cylinders.

g is the valve, here shown having the general form of a section of a cylinder and operating in a cylindrical seat comprising, as seen in Fig. 3, scarcely one-half of a circle, so it may be permitted to rise inv-its seat on emergencies, and being formed of twolongitudinal and transverse arched walls terminating, respectively, in faces 9 g and 9 said walls being separated from-each other by an ample space 9, serving as atransverse channel-way through which low-pressure steam is conducted from a high to a low pressure cylinder, described farther on. Said valve is actuated in this case through means of the lever It, con- 'necting link or rod 71, rocker-arm jy", mounted in bracket or projection is, and means of connection through arm and yoke m to eccentric Z, secured to the main shaft 6 in this case.

The chamber g at under side of the valve is the cavity through which the exhauststeam from low-pressure cylinder passes out by way of f into atmosphere or condenser.

s is the high-pressure-steam-supply opening and being shown at point of admission, and

whereby on further motion steam will be admitted to the high-pressure or small section of piston through port f .and low-pressure or exhaust steam from the opposite small cylinder through port f, at the same time flowing through said port-channel g in valve is admitted through'port f into larger cylinder, while the exhaust from opposite larger cylinder is flowing through port f and exhaustcavity g and outlet f into condenser or atmosphere.

Any form of governor suitable to any ordinary slide-valve is adapted to operate my valve; but I prefer a good shaft-governor as being the most eflicient.

The valve here shown is adapted to any valvemotion suitable for ordinary slidevalves.

There area number of changes or alterations that may be resorted to in the particular arrangement of ports and shape of valve in my device, and I desire it understood that I hold myself at liberty to make any such al.

terations as fall fairly within the scope of my invention.

What I claim as new, and desire to secure by LettersPatent, is

1. In a compound steam-engine having two high-pressure single-acting cylinders and two low-pressure single-acting cylinders, a single oscillating valve located between the two highpressure cylinders and near the top of the lowpressure cylinders, and in such relation to the four cylinders as to admit steam to and ex viding thereby four admission edges or lips and an exhaust-chamber, as set forth.

3. In a single-acting, four-cylinder, compound engine, a semicircular valve located at right angles, and between the two high-pressure cylinders, and means whereby said valve may be actuated so as to cut off the steam at varying points of the stroke, as set forth.

4:. In a double compound, single-acting engine, each pair a low and a high pressure single-acting piston, mounted in suitable cylinders, one pair of said pistons connected to each crank of adouble crank-shaft having opposite cranks that the weight of one pair of pistons may balance that of the other pair and one reciprocating valve and steam channelway through it located between said pairs of pistons distributing steam to all cylinders of said double compound engine, as set forth.

5. In a compound steam-engine, cylinders and pistons operating therein, a valve having a double arch terminating in faces at each end bearing'upon the valve-seat, a space between the two arches forming a channel-way transversely through said valve-opening into the valve-seat, and adapted to register with ports adapted thereto, as set forth."

6. Ina compound engine, cylinders and pistons operating therein, a double valve, a lowpressure supply channel in said valve, extending from end to end of port, two highpressure ports in a valve-seat adapted to said valve, an exhaust-opening at an intermediate point between said ports, and two low-pres sure ports'locate'd at each side of said exhaustopening, between the latter and said highpressure ports, as set forth.

7. In a four-cylinder compound engine, suitable cylinders and pistons operating therein, a valve-seat, a central exhaust-opening in said seat, as in ordinary slide-valveseats, a reciprocating valve sliding on said seat, a central exhaust-cavity in said valve in constant communication with said opening, an arched channel-way through the body of said valve opening into the lap or face surface thereof, on both sides of said exhaust-cavity and thereby forming two lap or face surfaces at each side of said valve, and two ports in said seat at each side of said exhaust-opening adapted respectively to be controlled by said lap-surfaces, the outer said ports communicating with'the high-pressure cylinders and the inner said ports communicating with the low-pressure cylinders, as set-forth.

ThatI claim the foregoing I have signed my name hereunto, this ith day of February, 1902,

in the presence of witnesses.

JAMES B. ALLFREE. Witnesses: E. B. HETZEL, D. H. PALMER. 

